1. Technical Field
The present invention relates to an image display apparatus and a method of controlling an image display apparatus.
2. Related Art
In the related art, in an image display apparatus, such as a projector, display control, such as dimming or luminance expansion processing, is performed based on a feature quantity of an image to be displayed (for example, see Japanese Patent No. 4432933). A projector described in Japanese Patent No. 4432933 performs appropriate luminance expansion processing and dimming corresponding to the feature quantity of the image, thereby increasing contrast of the image and suppressing halation of the image.
On the other hand, an image displayed on the image display apparatus may be attached with information other than the image. For example, in order to compensate for the difference between a display aspect ratio of the image display apparatus and an aspect ratio of an input image, a letter box image attached with black bands on the upper and lower sides or the right and left sides of an image may be displayed. A subtitle may be attached to an image. In this case, when obtaining a feature quantity of an image, additional information, such as a black band or a subtitle, is likely to affect a feature quantity. However, in order to increase display quality of an image by luminance expansion processing or dimming, it is preferable to use a feature quantity of an original input image other than the additional information as a reference. For this reason, there is a demand for a technique which obtains a feature quantity of an image in spite of an influence of additional information.